论文部分内容阅读
目的:通过牙齿移动距离的差异、牙周组织中破牙骨质细胞数量的变化及牙根吸收面积的差异,研究伊班膦酸钠对大鼠正畸源性牙根吸收的作用。方法:48只SPF级雌性Wistar大鼠,建立正畸牙齿移动动物模型,设置自身对照,对照侧为对侧未注药侧。在大鼠上颌双侧第一磨牙与上切牙之间安置一0.012英寸镍钛拉簧,施力60 g左右,所有大鼠均于安装矫治器前3 d在实验侧(大鼠上颌左侧)移动牙齿近中腭侧黏骨膜下局部注射50μL伊班膦酸钠,对照侧(大鼠上颌右侧)注射50μL 0.9%氯化钠液。每3 d注射一次直至实验结束。实验第3、7、14 d随机选择8只大鼠处死。分离大鼠头颅骨,用游标卡尺(精确度0.02 mm)测量上颌双侧第一磨牙移动的距离,并制备大鼠第一磨牙及其牙周组织切片,HE染色观察两侧牙周组织形态学变化,观察破牙骨质细胞的数量,采用图像处理软件对两侧的牙根吸收指数进行分析。结果:①牙齿移动距离随实验时间延长逐渐增加,组间比较:实验第3 d,实验侧和对照侧的牙齿移动距离平均值差异无统计学意义;实验第7 d和14 d,实验侧的牙齿移动距离均小于对照侧,差异具有统计学意义(P<0.05)。②实验侧第3 d、7 d和14 d大鼠第一磨牙牙周组织压力侧破牙骨质细胞数量均小于对照侧,且第7 d和14 d结果差异具有统计学意义(P<0.05)。③实验侧第3 d、7 d和14 d大鼠牙根吸收指数均小于对照侧,牙根吸收程度均比对照侧轻,且第7 d和14 d结果差异具有统计学意义(P<0.05)。结论:局部应用伊班膦酸钠可以减缓正畸牙齿移动的速度,减少牙周组织压力侧破牙骨质细胞的数量,减少正畸源性牙根吸收的发生。
OBJECTIVE: To study the effect of ibandronate on orthodontic tooth root resorption in rats through the difference of tooth movement distance, the number of periodontal tissue broken tooth alveolar cells and the root resorption area. Methods: Forty-eight SPF female Wistar rats were established. Animal models of orthodontic tooth movement were established. The control group was contralateral without injection. A 0.012-inch nickel-titanium tension spring was placed between the maxillary bilateral first molar and the incisor, with a force of about 60 g. All rats were on the experimental side 3 days before the appliance was installed ) 50μL ibandronate was injected submucosally into the mesial palatal mucosa and 50μL of 0.9% sodium chloride solution was injected into the control side (rat maxillary right). Injection every 3 d until the end of the experiment. On the 3rd, 7th and 14th days, 8 rats were randomly selected and sacrificed. The skull of the rat was separated and the movement of the first maxillary molars was measured with a vernier caliper (accuracy of 0.02 mm). The first molars of the rats and their periodontal tissue sections were prepared and the morphological changes of both sides of the periodontal tissues were observed by HE staining , Observe the number of broken tooth cells, using the image processing software on both sides of the root resorption index analysis. Results: (1) The distance of tooth movement increased with the extension of experimental time. Comparing between two groups, there was no significant difference in the mean value of tooth movement between the experimental side and the control side on the 3rd day of the experiment. On the 7th and 14th day, The moving distance of teeth was smaller than the control side, the difference was statistically significant (P <0.05). (2) The number of periodontal tissue pressure-side broken alveolar bone cells on the 3rd, 7th and 14th day in experimental group were less than that on the control side, and the difference was statistically significant on the 7th and 14th day (P <0.05 ). (3) The root resorption index of the rats on the 3rd, 7th and 14th day in experimental group were all less than those in the control side, and the root resorption degree was lighter than that in the control side. The difference between the 7th and 14th day was statistically significant (P <0.05). CONCLUSION: Topical application of ibandronate can slow the rate of orthodontic tooth movement, reduce the amount of broken periodontal ligament cells and decrease the occurrence of orthodontic root resorption.